Thank you everyone for replies. I understood my mistakes in thinking. Now, I am confirmed Binance is doing these only to attract big or new investors to gain more volume and to spread it widely! By doing this binance is spending 1.1 million USD, they are not getting money by giving away. So, this is a great and normal promotion scheme. Actually, I expected giveaways from Binance like Kucoin is doing, that's why my thought was that.
Thank you again, this is how this forum helps everyone, I had miss understanding or confusion, now I got the point.